In general, semiconductor elements are manufactured in a clean room whose internal atmosphere has been cleaned. Semiconductor wafers also need to be protected from contamination caused by the adhesion of impurities such as dirt and dust and a chemical reaction during the storage of semiconductor wafers that will serve as the material for the semiconductor elements and the transport of the semiconductor elements between the manufacturing steps. JP 2008-159734A discloses such a storage facility for storing semiconductor wafers. This storage facility includes storage racks including a plurality of storage sections that store air-tight transport containers such as a FOUP (Front Opening Unified Pod) for accommodating semiconductor wafers. Also, this storage facility has a purge function for supplying an inactive gas such as nitrogen or argon to the transport containers in order to prevent contamination caused by natural oxidation or the like of the semiconductor wafers accommodated in the transport containers.
Each transport container (storing FOUP) for accommodating semiconductor wafers includes a cover and a bottom surface portion that constitute a casing, and forms a sealed space by the cover and the bottom surface portion. A plurality of semiconductor wafers can be accommodated in the sealed space along the height direction. Recessed portions serving as a flow inlet and a flow outlet for gas are formed on the underside of the bottom surface portion, and the recessed portions are configured to be able to be joined to pipes of a purge unit that supplies an inactive gas. Placing a transport container on the purge unit causes the recessed portions and the pipes to be joined together, thereby enabling the inactive gas to be supplied to that transport container. Here, in order to confirm whether the inactive gas is appropriately supplied to the transport container, the flow rate of the inactive gas may be measured. In JP 2008-159734A, an inspection apparatus (measurement FOUP) is used for measuring the flow rate of the inactive gas. A flow inlet and a flow outlet capable of being joined to the pipes of the purge unit by placing the inspection apparatus on the purge unit are also formed on the bottom surface of the inspection apparatus (measurement FOUP). The inspection apparatus includes a flowmeter, and the flow rate of the inactive gas can be measured by placing the inspection apparatus on the purge unit, in place of the transport container (JP 2008-159734A: paragraphs 0032 to 0036, etc.).